1 //===- llvm/CodeGen/DwarfCompileUnit.h - Dwarf Compile Unit -----*- C++ -*-===// 2 // 3 // Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions. 4 // See https://llvm.org/LICENSE.txt for license information. 5 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception 6 // 7 //===----------------------------------------------------------------------===// 8 // 9 // This file contains support for writing dwarf compile unit. 10 // 11 //===----------------------------------------------------------------------===// 12 13 #ifndef LLVM_LIB_CODEGEN_ASMPRINTER_DWARFCOMPILEUNIT_H 14 #define LLVM_LIB_CODEGEN_ASMPRINTER_DWARFCOMPILEUNIT_H 15 16 #include "DwarfDebug.h" 17 #include "DwarfUnit.h" 18 #include "llvm/ADT/ArrayRef.h" 19 #include "llvm/ADT/DenseMap.h" 20 #include "llvm/ADT/SmallVector.h" 21 #include "llvm/ADT/StringMap.h" 22 #include "llvm/ADT/StringRef.h" 23 #include "llvm/BinaryFormat/Dwarf.h" 24 #include "llvm/CodeGen/DbgEntityHistoryCalculator.h" 25 #include "llvm/CodeGen/DIE.h" 26 #include "llvm/CodeGen/LexicalScopes.h" 27 #include "llvm/IR/DebugInfoMetadata.h" 28 #include "llvm/Support/Casting.h" 29 #include <algorithm> 30 #include <cassert> 31 #include <cstdint> 32 #include <memory> 33 34 namespace llvm { 35 36 class AsmPrinter; 37 class DwarfFile; 38 class GlobalVariable; 39 class MCExpr; 40 class MCSymbol; 41 class MDNode; 42 43 enum class UnitKind { Skeleton, Full }; 44 45 class DwarfCompileUnit final : public DwarfUnit { 46 /// A numeric ID unique among all CUs in the module 47 unsigned UniqueID; 48 bool HasRangeLists = false; 49 50 /// The attribute index of DW_AT_stmt_list in the compile unit DIE, avoiding 51 /// the need to search for it in applyStmtList. 52 DIE::value_iterator StmtListValue; 53 54 /// Skeleton unit associated with this unit. 55 DwarfCompileUnit *Skeleton = nullptr; 56 57 /// The start of the unit within its section. 58 MCSymbol *LabelBegin; 59 60 /// The start of the unit macro info within macro section. 61 MCSymbol *MacroLabelBegin; 62 63 using ImportedEntityList = SmallVector<const MDNode *, 8>; 64 using ImportedEntityMap = DenseMap<const MDNode *, ImportedEntityList>; 65 66 ImportedEntityMap ImportedEntities; 67 68 /// GlobalNames - A map of globally visible named entities for this unit. 69 StringMap<const DIE *> GlobalNames; 70 71 /// GlobalTypes - A map of globally visible types for this unit. 72 StringMap<const DIE *> GlobalTypes; 73 74 // List of ranges for a given compile unit. 75 SmallVector<RangeSpan, 2> CURanges; 76 77 // The base address of this unit, if any. Used for relative references in 78 // ranges/locs. 79 const MCSymbol *BaseAddress = nullptr; 80 81 DenseMap<const MDNode *, DIE *> AbstractSPDies; 82 DenseMap<const DINode *, std::unique_ptr<DbgEntity>> AbstractEntities; 83 84 /// DWO ID for correlating skeleton and split units. 85 uint64_t DWOId = 0; 86 87 /// Construct a DIE for the given DbgVariable without initializing the 88 /// DbgVariable's DIE reference. 89 DIE *constructVariableDIEImpl(const DbgVariable &DV, bool Abstract); 90 91 bool isDwoUnit() const override; 92 93 DenseMap<const MDNode *, DIE *> &getAbstractSPDies() { 94 if (isDwoUnit() && !DD->shareAcrossDWOCUs()) 95 return AbstractSPDies; 96 return DU->getAbstractSPDies(); 97 } 98 99 DenseMap<const DINode *, std::unique_ptr<DbgEntity>> &getAbstractEntities() { 100 if (isDwoUnit() && !DD->shareAcrossDWOCUs()) 101 return AbstractEntities; 102 return DU->getAbstractEntities(); 103 } 104 105 void finishNonUnitTypeDIE(DIE& D, const DICompositeType *CTy) override; 106 107 public: 108 DwarfCompileUnit(unsigned UID, const DICompileUnit *Node, AsmPrinter *A, 109 DwarfDebug *DW, DwarfFile *DWU, 110 UnitKind Kind = UnitKind::Full); 111 112 bool hasRangeLists() const { return HasRangeLists; } 113 unsigned getUniqueID() const { return UniqueID; } 114 115 DwarfCompileUnit *getSkeleton() const { 116 return Skeleton; 117 } 118 119 bool includeMinimalInlineScopes() const; 120 121 void initStmtList(); 122 123 /// Apply the DW_AT_stmt_list from this compile unit to the specified DIE. 124 void applyStmtList(DIE &D); 125 126 /// A pair of GlobalVariable and DIExpression. 127 struct GlobalExpr { 128 const GlobalVariable *Var; 129 const DIExpression *Expr; 130 }; 131 132 struct BaseTypeRef { 133 BaseTypeRef(unsigned BitSize, dwarf::TypeKind Encoding) : 134 BitSize(BitSize), Encoding(Encoding) {} 135 unsigned BitSize; 136 dwarf::TypeKind Encoding; 137 DIE *Die = nullptr; 138 }; 139 140 std::vector<BaseTypeRef> ExprRefedBaseTypes; 141 142 /// Get or create global variable DIE. 143 DIE * 144 getOrCreateGlobalVariableDIE(const DIGlobalVariable *GV, 145 ArrayRef<GlobalExpr> GlobalExprs); 146 147 DIE *getOrCreateCommonBlock(const DICommonBlock *CB, 148 ArrayRef<GlobalExpr> GlobalExprs); 149 150 void addLocationAttribute(DIE *ToDIE, const DIGlobalVariable *GV, 151 ArrayRef<GlobalExpr> GlobalExprs); 152 153 /// addLabelAddress - Add a dwarf label attribute data and value using 154 /// either DW_FORM_addr or DW_FORM_GNU_addr_index. 155 void addLabelAddress(DIE &Die, dwarf::Attribute Attribute, 156 const MCSymbol *Label); 157 158 /// addLocalLabelAddress - Add a dwarf label attribute data and value using 159 /// DW_FORM_addr only. 160 void addLocalLabelAddress(DIE &Die, dwarf::Attribute Attribute, 161 const MCSymbol *Label); 162 163 DwarfCompileUnit &getCU() override { return *this; } 164 165 unsigned getOrCreateSourceID(const DIFile *File) override; 166 167 void addImportedEntity(const DIImportedEntity* IE) { 168 DIScope *Scope = IE->getScope(); 169 assert(Scope && "Invalid Scope encoding!"); 170 if (!isa<DILocalScope>(Scope)) 171 // No need to add imported enities that are not local declaration. 172 return; 173 174 auto *LocalScope = cast<DILocalScope>(Scope)->getNonLexicalBlockFileScope(); 175 ImportedEntities[LocalScope].push_back(IE); 176 } 177 178 /// addRange - Add an address range to the list of ranges for this unit. 179 void addRange(RangeSpan Range); 180 181 void attachLowHighPC(DIE &D, const MCSymbol *Begin, const MCSymbol *End); 182 183 /// Find DIE for the given subprogram and attach appropriate 184 /// DW_AT_low_pc and DW_AT_high_pc attributes. If there are global 185 /// variables in this scope then create and insert DIEs for these 186 /// variables. 187 DIE &updateSubprogramScopeDIE(const DISubprogram *SP); 188 189 void constructScopeDIE(LexicalScope *Scope, 190 SmallVectorImpl<DIE *> &FinalChildren); 191 192 /// A helper function to construct a RangeSpanList for a given 193 /// lexical scope. 194 void addScopeRangeList(DIE &ScopeDIE, SmallVector<RangeSpan, 2> Range); 195 196 void attachRangesOrLowHighPC(DIE &D, SmallVector<RangeSpan, 2> Ranges); 197 198 void attachRangesOrLowHighPC(DIE &D, 199 const SmallVectorImpl<InsnRange> &Ranges); 200 201 /// This scope represents inlined body of a function. Construct 202 /// DIE to represent this concrete inlined copy of the function. 203 DIE *constructInlinedScopeDIE(LexicalScope *Scope); 204 205 /// Construct new DW_TAG_lexical_block for this scope and 206 /// attach DW_AT_low_pc/DW_AT_high_pc labels. 207 DIE *constructLexicalScopeDIE(LexicalScope *Scope); 208 209 /// constructVariableDIE - Construct a DIE for the given DbgVariable. 210 DIE *constructVariableDIE(DbgVariable &DV, bool Abstract = false); 211 212 DIE *constructVariableDIE(DbgVariable &DV, const LexicalScope &Scope, 213 DIE *&ObjectPointer); 214 215 /// Construct a DIE for the given DbgLabel. 216 DIE *constructLabelDIE(DbgLabel &DL, const LexicalScope &Scope); 217 218 /// A helper function to create children of a Scope DIE. 219 DIE *createScopeChildrenDIE(LexicalScope *Scope, 220 SmallVectorImpl<DIE *> &Children, 221 bool *HasNonScopeChildren = nullptr); 222 223 void createBaseTypeDIEs(); 224 225 /// Construct a DIE for this subprogram scope. 226 DIE &constructSubprogramScopeDIE(const DISubprogram *Sub, 227 LexicalScope *Scope); 228 229 DIE *createAndAddScopeChildren(LexicalScope *Scope, DIE &ScopeDIE); 230 231 void constructAbstractSubprogramScopeDIE(LexicalScope *Scope); 232 233 /// This takes a DWARF 5 tag and returns it or a GNU analog. 234 dwarf::Tag getDwarf5OrGNUTag(dwarf::Tag Tag) const; 235 236 /// This takes a DWARF 5 attribute and returns it or a GNU analog. 237 dwarf::Attribute getDwarf5OrGNUAttr(dwarf::Attribute Attr) const; 238 239 /// This takes a DWARF 5 location atom and either returns it or a GNU analog. 240 dwarf::LocationAtom getDwarf5OrGNULocationAtom(dwarf::LocationAtom Loc) const; 241 242 /// Construct a call site entry DIE describing a call within \p Scope to a 243 /// callee described by \p CalleeSP. 244 /// \p IsTail specifies whether the call is a tail call. 245 /// \p PCAddr (used for GDB + DWARF 4 tuning) points to the PC value after 246 /// the call instruction. 247 /// \p PCOffset (used for cases other than GDB + DWARF 4 tuning) must be 248 /// non-zero for non-tail calls (in the case of non-gdb tuning, since for 249 /// GDB + DWARF 5 tuning we still generate PC info for tail calls) or be the 250 /// function-local offset to PC value after the call instruction. 251 /// \p CallReg is a register location for an indirect call. For direct calls 252 /// the \p CallReg is set to 0. 253 DIE &constructCallSiteEntryDIE(DIE &ScopeDIE, const DISubprogram *CalleeSP, 254 bool IsTail, const MCSymbol *PCAddr, 255 const MCExpr *PCOffset, unsigned CallReg); 256 /// Construct call site parameter DIEs for the \p CallSiteDIE. The \p Params 257 /// were collected by the \ref collectCallSiteParameters. 258 /// Note: The order of parameters does not matter, since debuggers recognize 259 /// call site parameters by the DW_AT_location attribute. 260 void constructCallSiteParmEntryDIEs(DIE &CallSiteDIE, 261 SmallVector<DbgCallSiteParam, 4> &Params); 262 263 /// Construct import_module DIE. 264 DIE *constructImportedEntityDIE(const DIImportedEntity *Module); 265 266 void finishSubprogramDefinition(const DISubprogram *SP); 267 void finishEntityDefinition(const DbgEntity *Entity); 268 269 /// Find abstract variable associated with Var. 270 using InlinedEntity = DbgValueHistoryMap::InlinedEntity; 271 DbgEntity *getExistingAbstractEntity(const DINode *Node); 272 void createAbstractEntity(const DINode *Node, LexicalScope *Scope); 273 274 /// Set the skeleton unit associated with this unit. 275 void setSkeleton(DwarfCompileUnit &Skel) { Skeleton = &Skel; } 276 277 unsigned getHeaderSize() const override { 278 // DWARF v5 added the DWO ID to the header for split/skeleton units. 279 unsigned DWOIdSize = 280 DD->getDwarfVersion() >= 5 && DD->useSplitDwarf() ? sizeof(uint64_t) 281 : 0; 282 return DwarfUnit::getHeaderSize() + DWOIdSize; 283 } 284 unsigned getLength() { 285 return sizeof(uint32_t) + // Length field 286 getHeaderSize() + getUnitDie().getSize(); 287 } 288 289 void emitHeader(bool UseOffsets) override; 290 291 /// Add the DW_AT_addr_base attribute to the unit DIE. 292 void addAddrTableBase(); 293 294 MCSymbol *getLabelBegin() const { 295 assert(getSection()); 296 return LabelBegin; 297 } 298 299 MCSymbol *getMacroLabelBegin() const { 300 return MacroLabelBegin; 301 } 302 303 /// Add a new global name to the compile unit. 304 void addGlobalName(StringRef Name, const DIE &Die, 305 const DIScope *Context) override; 306 307 /// Add a new global name present in a type unit to this compile unit. 308 void addGlobalNameForTypeUnit(StringRef Name, const DIScope *Context); 309 310 /// Add a new global type to the compile unit. 311 void addGlobalType(const DIType *Ty, const DIE &Die, 312 const DIScope *Context) override; 313 314 /// Add a new global type present in a type unit to this compile unit. 315 void addGlobalTypeUnitType(const DIType *Ty, const DIScope *Context); 316 317 const StringMap<const DIE *> &getGlobalNames() const { return GlobalNames; } 318 const StringMap<const DIE *> &getGlobalTypes() const { return GlobalTypes; } 319 320 /// Add DW_AT_location attribute for a DbgVariable based on provided 321 /// MachineLocation. 322 void addVariableAddress(const DbgVariable &DV, DIE &Die, 323 MachineLocation Location); 324 /// Add an address attribute to a die based on the location provided. 325 void addAddress(DIE &Die, dwarf::Attribute Attribute, 326 const MachineLocation &Location); 327 328 /// Start with the address based on the location provided, and generate the 329 /// DWARF information necessary to find the actual variable (navigating the 330 /// extra location information encoded in the type) based on the starting 331 /// location. Add the DWARF information to the die. 332 void addComplexAddress(const DbgVariable &DV, DIE &Die, 333 dwarf::Attribute Attribute, 334 const MachineLocation &Location); 335 336 /// Add a Dwarf loclistptr attribute data and value. 337 void addLocationList(DIE &Die, dwarf::Attribute Attribute, unsigned Index); 338 void applyVariableAttributes(const DbgVariable &Var, DIE &VariableDie); 339 340 /// Add a Dwarf expression attribute data and value. 341 void addExpr(DIELoc &Die, dwarf::Form Form, const MCExpr *Expr); 342 343 /// Add an attribute containing an address expression to \p Die. 344 void addAddressExpr(DIE &Die, dwarf::Attribute Attribute, const MCExpr *Expr); 345 346 void applySubprogramAttributesToDefinition(const DISubprogram *SP, 347 DIE &SPDie); 348 349 void applyLabelAttributes(const DbgLabel &Label, DIE &LabelDie); 350 351 /// getRanges - Get the list of ranges for this unit. 352 const SmallVectorImpl<RangeSpan> &getRanges() const { return CURanges; } 353 SmallVector<RangeSpan, 2> takeRanges() { return std::move(CURanges); } 354 355 void setBaseAddress(const MCSymbol *Base) { BaseAddress = Base; } 356 const MCSymbol *getBaseAddress() const { return BaseAddress; } 357 358 uint64_t getDWOId() const { return DWOId; } 359 void setDWOId(uint64_t DwoId) { DWOId = DwoId; } 360 361 bool hasDwarfPubSections() const; 362 363 void addBaseTypeRef(DIEValueList &Die, int64_t Idx); 364 }; 365 366 } // end namespace llvm 367 368 #endif // LLVM_LIB_CODEGEN_ASMPRINTER_DWARFCOMPILEUNIT_H 369